public class Demo1 {

    private static Object locker1=new Object();
    private static Object locker2=new Object();
    private static Object locker3=new Object();

    public static void main(String[] args) throws InterruptedException {
        Thread t1=new Thread(()-> {
            for(int i=0;i<10;i++) {
                synchronized (locker3) {
                    try {
                        locker3.wait();
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                }
                System.out.print("A");
                synchronized(locker1) {
                    locker1.notify();
                }
            }
        });

        Thread t2=new Thread(()-> {
            for(int i=0;i<10;i++) {
                synchronized(locker1) {
                    try {
                        locker1.wait();
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                }
                System.out.print("B");
                synchronized(locker2) {
                    locker2.notify();
                }
            }
        });

        Thread t3=new Thread(()-> {
            for(int i=0;i<10;i++) {
                synchronized(locker2) {
                    try {
                        locker2.wait();
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }
                }
                System.out.println("C");
                synchronized(locker3) {
                    locker3.notify();
                }
            }
        });
        t1.start();
        t2.start();
        t3.start();

        Thread.sleep(100);//主线程先sleep,确保所有线程都已进入wait
        //主线程唤醒t1,推了t1一把,然后就顺利成章进入循环了
        synchronized (locker3) {
            locker3.notify();
        }
    }
}
